[PATCH v3 32/35] x86/bugs: Add attack vector controls for spectre_v2

David Kaplan
2025-01-08T20:26:03Z

Use attack vector controls to determine if spectre_v2 mitigation is
required.

Signed-off-by: David Kaplan <david.kaplan@amd.com>
---
arch/x86/kernel/cpu/bugs.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 57c762d86fca..662573ad3e51 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2041,13 +2041,15 @@ static void __init spectre_v2_select_mitigation(void)
case SPECTRE_V2_CMD_NONE:
return;

- case SPECTRE_V2_CMD_FORCE:
case SPECTRE_V2_CMD_AUTO:
+ if (!should_mitigate_vuln(X86_BUG_SPECTRE_V2))
+ break;
+ fallthrough;
+ case SPECTRE_V2_CMD_FORCE:
if (boot_cpu_has(X86_FEATURE_IBRS_ENHANCED)) {
mode = SPECTRE_V2_EIBRS;
break;
}
-
mode = spectre_v2_select_retpoline();
break;

--
2.34.1